


Practical Ethics for Beginners

by Persiflager



Category: Sherlock (TV), Sherlock Holmes & Related Fandoms
Genre: Alternate Universe - College/University, M/M, Teacher-Student Relationship
Language: English
Status: Completed
Published: 2012-07-01
Updated: 2012-07-01
Packaged: 2017-11-08 23:21:12
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 9,387
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/448681
Author URL: https://archiveofourown.org/users/Persiflager/pseuds/Persiflager
Summary: <blockquote class="userstuff">
              <p>Written for <a href="http://sherlockbbc-fic.livejournal.com/17487.html?thread=108568143#t108568143"> this prompt</a> on the kinkmeme that asked for a Professor!Mycroft/Student!John AU.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> [TheDugongG](http://archiveofourown.org/users/TheDugongG) has very kindly posted a Chinese translation [here.](http://www.allwatson.com/forum.php?mod=viewthread&tid=871&extra=page%3D1)

The February rain had settled into a steady drizzle by the time John made his way round to the back entrance of the Chemistry building where Sherlock was skulking. 

“You’re late,” he said, taking a drag from his cigarette and sending a resentful puff of smoke into John’s face. John waved it away automatically and ran a hand over his face to wipe off the worst of the rain.

“Yes, well. Some of us do actually have to show up for lectures from time to time,” said John as he dug a packet of crisps out of his pocket, opened them, and thrust them in Sherlock’s direction. Sherlock deigned to take a handful before waving the packet away.

“And was it a worthwhile use of your time?” 

“Yeah, actually, it was good. He was really good,” said John through a mouthful of crisps.

Sherlock frowned. “He?”

John crumpled the empty packet and tossed it in a nearby bin. “Mm, new lecturer. Professor Holmes, funnily enough. Any relation?”

What should have been the last, delicious drag of Sherlock’s cigarette turned into an undignified choking fit. John fished a bottle of water out of his bag and watched with concern as Sherlock drank it until the wheezing had subsided.

“Those really aren’t good for you,” he said mildly. 

Sherlock ignored the smugness of his _told you so_ eyebrows. “If you dare to suggest any likeness between me and that corpulent cretin, I’ll set fire to your bed.”

“You have set fire to my bed. And Mike’s.”

“This time I won’t put it out.”

John seemed unperturbed by the threat. “So, not a nice man?”

“He abuses power as mercilessly as you abuse technology,” insisted Sherlock. “Stay well away from him.”

“Sounds just... awful,” said John absently. 

Sherlock snapped his fingers in front of John’s face to make him focus. “Exactly. Now let’s abandon this tedious conversation in favour of something interesting; those lungfish won’t dissect themselves.”

John nodded. Sherlock congratulated himself on a crisis averted and led the way to the upstairs lab he’d co-opted for his more gruesome experiments.

..........................

John didn’t take Sherlock’s warning seriously, especially once he found out that Professor Holmes chaired the committee that had denied Sherlock permission to carry out some of his more morally dubious experiments on students. He did, however, keep it in mind, and one week later he found himself sitting in the back of a crowded lecture theatre and dividing his attention between taking notes and ogling the professor. His favourite ‘blackmailed into sex by unscrupulous but attractive authority figure’ fantasy had got a new leading actor, and he wanted to get as many of the details right as possible.

John was aware that fantasising that particular scenario about a man who taught medical ethics was an extra level of inappropriateness, but frankly that only made it hotter. The only downside was that it was an area in which he was genuinely interested. How was he supposed on what Professor Holmes was saying when he looked like _that_?

Professor Holmes was a tall, well-proportioned man who moved with a lovely, languid physical confidence. He was dressed in an immaculate three-piece suit with neat auburn hair, shined shoes and a pocket square. The contrast between his stiff, buttoned-up exterior and the immoral, lascivious personality that John had ascribed to him was ball-achingly erotic. Add to that his smooth, cultured tones and the way he alternated waving the pointer lazily about and thwacking it forcefully on the blackboard, and John had been uncomfortably erect for the past quarter of an hour.

John decided to get his mind back on track. Pinching his thigh forcefully, he concentrated as hard as he could on the professor’s final words.

“And that point is rather nicely made in Ecclesiastes, chapter 1, verse 18: ‘In much wisdom is grief: and he that increaseth knowledge increaseth sorrows,” said Professor Holmes, leaning on the lectern with one hand. “I therefore congratulate the majority of you on the undoubtedly blissful lives that you are to lead.”

John suppressed a laugh but couldn’t help himself smiling at that. Professor Holmes paused to glance in John’s direction before continuing.

“If, however, you are willing to contribute to the sorrows of the world, I should be grateful if you would spare some of your time to complete a short survey on your personal ethics,” said the professor, waving at a stack of papers by the door. “The survey is, of course, completely anonymous.”

The clock struck two and anything else the professor had to say was lost in the noise of a hundred students talking at once. John hastened to pack up his notes and joined the crowd heading out of the lecture theatre, hardly any of whom picked up the survey on their way. John was struck by a wave of guilt.

“Thank you,” said Professor Holmes as John took one of the surveys from the pile. He looked pleasantly surprised.

“John Watson,” said John, sticking his hand out on a sudden impulse. “Um, I’m really enjoying the class.”

Professor Holmes looked at John’s outstretched hand for a moment before clasping it in his own warm hand. “I’m glad,” he said, shaking John’s hand firmly before releasing it. “Please call me Mycroft.”

“Alright,” said John with a quick grin. “See you next week.” Mycroft gave him a curious, assessing look before smiling slightly in return. 

“Until next week, John.”

John made a hurried exit from the lecture theatre before he could say anything to embarrass himself. _What a nice man_ , he thought as he stuffed the survey into his bag before heading over to the Chemistry building to meet Sherlock. _He’s a nice, polite, respectable man who’s an excellent teacher, and I’m going to the special hell for what I’m about to make him do in my dreams._

..........................

Sunday morning is usually the quietest time in a student household, which is why Sherlock made the once-a-week herculean effort to get up early and conduct his more delicate experiments. He was frowning down his eyepiece of his microscope when he heard the kitchen door swing open behind him.

“Two sugars in mine today. Oh, and get the other fungus slides out of the fridge, I’ll be wanting them in a minute,” he said before a stray whiff of Lynx deodorant made him look up in surprise.

“Good morning to you too,” said Mike, yawning as he stumbled past Sherlock to fill the kettle. “Blimey, my head is killing me. Don’t ever trust Molly’s cocktails, by the way.”

“Where’s John?” asked Sherlock, leaning back precariously on his chair and glancing at the clock. “It’s gone eleven; he’s usually come down for tea by now.”

“Isn’t he in his room?”

Sherlock glared at him. “If I knew that, why would I ask you?”

Mike shrugged and opened the fridge. “I don’t know why you do most of the things you do. Didn’t we have some eggs left?”

“Needed them for an experiment,” said Sherlock distractedly, ignoring Mike’s sigh. “Kettle’s boiled.”

Sherlock stood up and marched upstairs, leaving Mike to yawn and make tea in three mis-matched mugs.

The door to John’s room was shut but there were faint sounds of movement within – pen on paper, a tapping foot, the creak of a chair. Sherlock flung open the door to see John sitting and working at his desk.

“Oh, morning,” said John, turning round and casually resting one arm on top of the pages he’d been working on. Sherlock narrowed his eyes. There were numerous explanations for the uncharacteristic alteration to John’s schedule, but only one that coincided with an increased desire for privacy and a faint blush on the back of his neck; John had, or would soon have, a new girlfriend or boyfriend.

Sherlock kept a spreadsheet tracking the various annoying aspects of John’s various romantic dalliances in the hope that one day he would be able to optimise the formula and find the most Sherlock-acceptable partner. It hadn’t gone very well so far; he’d had to add a new column for each individual, as they each managed to have a uniquely irritating trait. He hadn’t even managed to determine whether the optimal partner would be male or female, as he couldn’t decide whether to give greater weighting to ‘pitch of voice renders sex noises most audible’ or ‘most likely to try to make conversation with Sherlock in the mornings’.

“If you’re looking for your skull, I think Mike put it in the – hey!”

Probably due to the lack of caffeine, John’s reactions were too slow to stop Sherlock retreating victorious to the doorway with the top sheet of paper in his hand.

He read the first question (to which John had provided an unsurprisingly idealistic response): _You are asked by a minor government official to provide regular reports on a close friend’s health and eating habits. How much money would you require per month to accept? Assume for the purposes of the question that the offer is legitimate and will have no negative consequences for your friend._

Sherlock scowled and skimmed through the rest of the page.

“Where did you get this?” he demanded, waving the paper at John.

“It’s for some people in the psychology department, I think” said John, who finally succeeded in wrestling the page off Sherlock. “Look, there’s a voucher for half-off at Speedy’s.”

“You’ve sold your soul for a half-price sandwich.”

John threw his hands up. “What are you talking about? It’s just a survey.”

Sherlock stared at him for a moment. “Mike’s made tea,” he said eventually, at which pronouncement John shot downstairs. Sherlock took a moment to scan John’s room for any further evidence of the encroaching horror before whipping out his phone.

_Don’t even THINK about recruiting him. SH_

The response was immediate.

_And why shouldn’t I? MH_

_Because I’ll make your life hell if you do. SH_

_Please explain how that would differ from the present. MH_

_Fine. 16 June 1994. SH_

The phone stayed silent for a few minutes. Sherlock was half-way down the stairs when it buzzed again.

_Hmm... I don’t think so. Try harder. MH_

..........................

Two days later, Mycroft was setting up the overhead projector for his lecture when John came in just ahead of a swarm of other students. He caught Mycroft’s eye, grinned and waved enthusiastically. Mycroft made himself wait for a moment before smiling in recognition and giving a small wave back.

The indulgence of watching John’s firm, muscular, denim-clad arse bound up the stairs to his seat near the back of the room was even more enjoyable than he’d predicted. Mycroft considered the fraternal negotiations of the past forty-eight hours, made up his mind, and sent a quick text while his students were settling down.

_Very well. I accept your last offer, contingent upon delivery by the 30th. MH_

Mycroft noticed out of the corner of his eye that John was now nibbling absent-mindedly on a pencil. He straightened up and looked calmly around the room before speaking.

“Good afternoon,” he said in his most mild-mannered tone. “Today we are going to be discussing the ethical problems caused by sexual relationships between doctors and patients.”

The sound of a pencil snapping halfway through that sentence really was extraordinarily satisfying.


	2. Chapter 2

John came home to find Mike in the kitchen, indulging in his afternoon ritual of tea, biscuits and newspaper. He nodded at John before going straight back to his paper.

John took a moment to appreciate Mike as a friend and housemate. It was a wonderful thing to spend time with someone who couldn’t tell from a seven-minute delay and the slight blush on John’s ears that he’d had to hide in the toilets for a hurried post-lecture wank before making his way home (in his defence, the way Mycroft caressed his pointer had been so suggestive that John had almost suspected him of doing it deliberately).

“Not like you to be home on a Tuesday,” said Mike eventually. “Where’s Sherlock today?”

John shrugged as he finished making himself a cup of tea. “Don’t know. He woke me up at five this morning, told me that he would be ‘unavoidably and annoyingly detained’ for a few days, gave me a list of instructions for taking care of his experiments, and made me promise on pain of death that I wouldn’t get into any cars with strangers.” Mike nodded sympathetically as John sat down on the other side of the table with his tea, helped himself to one of the newspapers from the pile and started reading.

John had to resist the urge to smack himself in the face when he realised that he was stopping on every article that contained the words ‘Holmes’, ‘homes’, ‘ethics’, ‘Professor’, ‘teacher’, ‘lecture’, ‘sex’ or ‘inappropriate’ . This crush was getting out of hand. As well as staring like a loon for an hour a week and masturbating every night to a variety of increasingly debauched and detailed fantasies starring Mycroft, he’d resorted to stalking him on the internet using the library computers (so that Sherlock didn’t notice it in his internet history). All he’d been able to find out was that Mycroft had been the youngest ever professor at the university when he took on his current post a year ago at the age of twenty-five, and he seemed to have his fingers in every academic pie going – philosophy, psychology, politics, even game theory. No personal information was available, and certainly nothing that could him work out whether Mycroft was (a) single, (b) attracted to men, and (c) likely to laugh in the face of a student asking him out for a drink.

The worst thing was that, based on admittedly shaky extrapolation from the available data, John thought that he might actually like Mycroft in more than a let’s-get-stark-bollock-naked-right-now way (although, to be fair, he really, _really_ liked him in that way). As well as his obvious hyper-intelligence, Mycroft seemed to have a dry sense of humour that John would like to hear more of in a non-academic setting. And, of course, all the evidence indicated that he was a man, as politicians would say, of ‘great personal integrity’, which sadly meant that the chances of him taking a risk on John were low. The only negative thing John had ever heard about him had been Sherlock’s vague comment about abusing power.

John had given up on the paper by this point. He watched Mike reading the gossip pages for a couple of minutes before inspiration struck.

“Mike?” he said with studied casualness. Mike responded with a grunt.

“You know our ethics professor?”

“Yes. I mean, not personally, no, but in a general sense, yes. Why?” Mike asked as he finally looked up.

“Have you heard anything ... funny about him?”

Mike gave John a long look before looking round the room with dramatic exaggeration and leaning in close. “MI5,” he said in a conspiratorial whisper. 

John looked at him with raised eyebrows. “Who did you hear that from?”

“Andrew Anderson.”

“He thinks that everyone’s trying to recruit him for the secret service. He spent two weeks speaking Russian to one of the cleaners because he thought she was an undercover agent.”

Mike shrugged. “Well, that’s what I heard.”

John tried to imagine Mycroft having secret meetings in car parks or running about with a gun. It didn’t seem very likely.

“Oh, I know what I was going to ask you,” said Mike suddenly. “What are you doing on Friday afternoon?”

John blinked at the change of subject. “Nothing, I think, unless Sherlock’s back by then. Why?”

“The Psychology department need volunteers for some experiments they’re running. I can’t do it, but I said I’d ask around. There’s a fifty quid in it for you if you stay for the full three hours.”

John thought for a moment before nodding. “Yeah, alright. Sign me up.”

 _This will be good_ , he thought. _It’ll distract me from being a creepy stalker, earn a bit of cash, and I’ll be contributing to science._

John whistled as he washed up their mugs like the good, considerate housemate that he was, and started thinking about all the productive things he could do while Sherlock was away: revision, coursework, gym. Maybe he’d even manage to finish a book without having the ending spoiled.

_After I’ve wanked my way through all the new ‘Mycroft is a kinky spy’ fantasies, of course. God, that would make for great porn. Think of the titles! The Spy Who Fucked Me? Thundercock? You Only Wank Twice (a day)? I should start writing these down._

.......................... 

John pedalled with grim determination as he stared at the video of someone cycling up a mountain on the TV screen in front of him. He’d been on the stationary bike for about half an hour – long enough for his thighs to be making some serious complaints - and couldn’t tell whether this experiment was because the psychology students had run out of ideas or because they were a bunch of sadists.

The previous experiments had been much more pleasant. He’d spent the first one rating the attractiveness of strangers based on pictures that flashed up on a computer screen accompanied by different background noises: rain, soft jazz, a car engine, birdsong, and the soundtrack to ‘Grange Hill’. He’d been slightly concerned that his results might be biased by not having had sex for a month, but there hadn’t been any space on the form to note that down.

For the next hour they’d been paired up to play variations on the Prisoner’s Dilemma. John’s partner had been a quiet, bearded man who got weirdly intense when they were given shiny tokens to bargain with. John had tried to just hand over his tokens in one of the rounds as he honestly thought the other student would enjoy having them more, but got glared at and told off for not taking the game seriously.

A movement in the corner of the gym distracted John from his thoughts. He glanced across to see Mycroft conferring over a clipboard with one of the administrators. He should have looked incongruous, wearing a three-piece suit in the gym, but somehow he just made everyone else look poorly dressed.

 _Fuck_. Just his luck to finally run into Mycroft outside of the lecture theatre when he was a sweaty, dishevelled mess. He kept his head down and prayed to every god that he could think of that Mycroft wouldn’t notice him.

“Hello John.”

“Mycroft! Hello,” said John, looking up with what he hoped was a convincing amount of surprise. “What are you doing here? I take it you’re not volunteering.”

“Supervising, actually,” said Mycroft absently as he made a note on his clipboard. “Eyes on the screen, if you’d be so kind.”

 _Oh, very smooth_ , thought John as Mycroft walked away to inspect the other volunteers. _Are you going to try passing him notes in class next?_

Mycroft didn’t come over again, although he seemed to have a fascination with checking his reflection in the mirrored wall behind John, and they were finally called to a halt ten minutes later. John clambered off the machine with a groan of relief and started stretching. 

“Was that as hellish as it seemed?”

Startled by Mycroft’s sudden re-appearance, John stood up too suddenly half-way through a stretch.

“Oh no, it was loads of fun. I’ll tell all my friends,” he said, wincing. “Was that actually a real experiment, or did they have a bet on to see who could make us suffer the most?”

“Forgive me if I mistrust a rugby-player’s definition of ‘fun’,” said Mycroft absently as he watched John rub and rotate his shoulder. John noticed that the humidity of the room had caused a lock of auburn hair to fall onto his forehead and start to curl. “And yes, it was for the sports science department. They’re terribly earnest.” 

John snorted at Mycroft’s world-weary tone. “Right. You do know that wearing a waistcoat doesn’t actually make you middle-aged?”

A smile tugged at the corner of Mycroft’s mouth. John grinned up at him, the endorphins still rushing through his system.

“Speaking of fun..,” he said, then something Mycroft had said struck him as odd. “Hang on a minute. How did you know that I played rugby?” 

Mycroft looked surprised at the question. He opened his mouth to reply but John’s brain had finally woken from its hormone-addled daze and put the clues together.

“Oh my god, you’re Sherlock’s brother.” 

.......................... 

“Of course,” said Mycroft, taking in the horrified expression on John’s face. “Ah. I see”

One of the graduate students running the experiment came up behind John and tapped him on the shoulder. Mycroft took advantage of the interruption to leave the room and walk briskly back to his office, where he sat down behind his desk and allowed himself a few moments to consider his error of judgement.

It had, on reflection, been foolish for him to believe that John might be interested in spite of the dreadful things he had undoubtedly heard from Sherlock. Now that he considered the matter objectively, unaffected by optimistic stirrings of his prick, it was obvious that Sherlock would choose to repudiate their connection and that John would take such a denial at face value.

It was a shame; he’d derived considerable enjoyment from discreetly encouraging John’s interest. The challenge of deducing John’s masturbatory fantasies had kept him entertained throughout each lecture, as well as furnishing him with new material for his own lengthy sessions of self-pleasure. Still, blackmailing a colleague to swap supervisory duties with him just so that he could observe John in skimpy gym shorts had perhaps been a step too far.

Perhaps it was for the best that this little flirtation had been brought to a halt before he’d truly embarrassed himself. Even if (as a purely academic exercise) he had used his observations of John’s personality, family and relationship history to map out the likely course of a hypothetical liaison to within a 5% error margin, it was unlikely that he would have taken the risk of becoming involved with an ex-student. He really had no reason to be feeling sorry for himself.

 _After all_ , thought Mycroft, _it’s not as if there is a deficit of trustworthy, intelligent, amusing young men who are not only able to tolerate but enjoy the company of a socially inadequate and morally dubious genius. Especially not ones who also have a backside I would gladly fuck six ways to Sunday._

Shaking his head, Mycroft put the matter aside and opened up his email inbox to look at the folder marked ‘Project Abel’. It had been five days since he’d sent Sherlock off to unearth instances of plagiarism and misconduct at several of England’s leading universities. Sherlock had not been in contact since – Mycroft expected that he would wait until the end to show off his conclusions – but there had been a torrent of outraged emails from the various academics who’d had the misfortune to cross his path. 

After a moment’s consideration, Mycroft decided that whisky was the appropriate drink to accompany a bout of Schadenfreude. He poured himself a glass of single malt from the bottle he had secreted in the bottom drawer of his desk and settled in to enjoy reading about people who were having even worse days than him.


	3. Chapter 3

John did not spend the remaining lectures in the same lusty fugue state as he had pre-horrifying-revelation; instead, he spent them making notes, highlighting printouts and looking at Mycroft in a wholly chaste and respectful manner. Thankfully, Mycroft appeared to have dispensed with his pointer. On the rare occasions that their eyes accidentally met, they exchanged the polite nods of acquaintances.

From the various cryptic hints that Sherlock had dropped in the past, John knew that Mycroft was Sherlock’s over-protective older brother, he was at least as observant as Sherlock, and the two of them didn’t exactly get on. John was inclined to ignore Sherlock’s more melodramatic comments – he might claim that Mycroft was his arch-nemesis, but Sherlock’s list of nemeses also included the man at the corner shop who refused to sell him more than 10 packs of cigarettes a day.

It was now clear to John that Mycroft had known who he was from the start and had (quite reasonably) assumed that John did likewise. He’d been friendly towards John in the gym because of John’s connection to Sherlock, not because he liked him. John would have taken some comfort in the fact that he hadn’t actually made it as far as making a pass at Mycroft if he didn’t know that his intentions would have been embarrassingly obvious. All he could be grateful for was that Mycroft didn’t seem to have taken offense, and that Sherlock (now back from his mysterious trip) either hadn’t noticed or didn’t care.

“Ah, there you are,” said Sherlock, his voice echoing round the deserted laboratory. “Took your time.”

“Well, that’s what happens when you text me at half ten on a Friday night.” John eyed the machines Sherlock was fiddling with doubtfully. “Are you sure it’s ok to be using all this? I thought the Haematology Department banned you after that thing with the pig.”

“You were watching ‘Grey’s Anatomy’ with Mike and glad of the distraction. And yes, one of the board members owes me a favour. Right, roll up your sleeve – I think half a pint should do it.”

Taking a few steps back, John crossed his arms.

“No.”

Sherlock finally looked up. “It’s for science.”

“Use your own.”

“I need rhesus negative,” said Sherlock in his most reasonable tone. “You’re not going to be much good as a doctor if you don’t get over this fear of needles.”

“Well, that’s the funny thing about doctoring,” said John, keeping a wary eye on Sherlock’s arms in case he made a sudden move for John’s blood, “it generally involves sticking the needles in other people. And, by the way, why do you know my blood type?”

Sherlock rolled his eyes in a very specific way that John had previously translated as _That question is too dull and has insufficient opportunities for showing off for me to bother answering it_. John was considering exit routes when he was distracted by his phone buzzing in his pocket.

“Leave it. It won’t be anyone important at this time of night, and this is much more interesting.” 

Ignoring Sherlock’s huff of annoyance, John pulled his phone out of his pocket.

“Good evening, John.”

John’s brain crossed some highly inappropriate synapses before he placed the voice. “Good evening, Mycroft. Um, what can I do for you?” He ignored Sherlock’s sudden frantic gestures to hang up.

“Would you be so kind as to inform my brother that, as of thirty minutes ago, Dr Lazenby has been suspended?”

“Dr Lazenby’s been suspended?” 

Sherlock stopped gesturing and frowned.

“Quite. Goodnight, John.” Mycroft hung up before John could reply.

John looked at his phone for a moment before shrugging and putting it away. “What’s that about?”

“Plagiarism, I suspect,” said Sherlock, grabbing a memory stick and a handful of printouts. “Or falsifying research. More importantly, why would my brother call you?”

“I don’t know. How does he have my number? And what do you mean, plagiarism?”

There was a distant thumping and the sound of shouting. Sherlock glanced towards the door of the laboratory.

“We have less than a minute before the security guards arrive. Fascinating as this conversation is, might I suggest that we finish it at home?”

John signalled his acquiescence by sprinting down the corridor.

......................

Once they’d made it home and got their breath back, John returned to his question.

“So,” he said, gingerly smearing antiseptic cream on the grazed knee he’d got climbing over a fence. “What exactly was this favour that you did? And it better be good, because you nearly got me arrested tonight.”

Sherlock had plugged his memory stick into John’s laptop and was working at the kitchen table. “Hm? Oh, that. In exchange for access to certain equipment, I agreed not to turn him into the university authorities.”

John looked at Sherlock with disbelief. “You blackmailed him.”

“In a manner of speaking.”

“And the fact that he’d falsified his research - that didn’t bother you at all? You, Mr Science, didn’t care that his data was flawed.”

Sherlock raised an eyebrow at the computer screen. “I’d hardly call social psychology science.”

“Compared to your work, you mean.”

“Yes, actually,” said Sherlock, sitting back in his chair and looking at John. “My work will revolutionise forensic science. Do you really think analysing people’s shopping habits or how they behave at a football match is in any way comparable?”

John held Sherlock’s stare for a moment before going to the freezer to see if there was any actual food in there. He rarely succeeded in winning arguments with Sherlock, and never on matters of principle (which Sherlock dismissed out of hand). Still, he occasionally managed to get the last word in his own way.

“Nice of your brother to warn us,” said John casually as he unearthed a frozen pizza and put it in the microwave.

“Mycroft is never nice,” said Sherlock, attention focused back on the computer screen in front of him.

“So you’re not going to thank him?” said John as he watched the pizza rotate. The rude noise behind him coincided with the ping of the microwave. He slid the pizza out, divided it between two plates and placed one in front of Sherlock, who shoved a slice into his mouth and went back to work.

“Fine. But if you won’t, then I will.” John ignored Sherlock’s undignified noise of protest and dialled Mycroft’s number.

“John! This is a pleasant surprise,” said Mycroft, sounding not very surprised at all.

“Hi Mycroft,” said John, walking backwards out of Sherlock’s reach. “Sorry for calling late. I hope I didn’t wake you up.”

“Not at all.”

“I just wanted to say thank you. For warning us, I mean. And Sherlock’s very grateful too.”

“That seems unlikely.”

“No, he’s really, really grateful,” said John, ducking the shoe that Sherlock threw at him. “We owe you one.”

“Do you really? How very interesting.”

John paused in his defensive manoeuvring for a moment to contemplate the lascivious purr that he’d almost certainly imagined in Mycroft’s voice.

“In that case, I should be very much obliged if you would persuade him to hand over the evidence.”

“Right. Yes, no problem,” said John glancing at Sherlock. “Will do.”

“Thank you. Goodnight, John.”

“Goodnight.”

John carefully put his phone away. “Well?” 

Sherlock was lying on the table in what John recognized as the prelude to an epic sulk. “I’m not giving it to him. If you’re so keen for him to have it, you’ll have to take it yourself.”

“Fine,” said John. 

Sherlock rolled over and opened his eyes a crack to glare at John. “Fine,” he snapped, retrieving another memory stick from his pocket and throwing it at a high enough angle that John had to jump to catch it. “Quisling.”

Taking the rest of the pizza with him, John beat a tactical retreat to his room.

............................

It was nearly five o’clock the next day when John found himself outside Mycroft’s office door on the fifth floor of the mathematics building.

_Remember the mission_ , thought John. _Hand over the memory stick, be polite, and get out as quickly as possible. Try not to think about him fucking you over the desk._

John straightened his shoulders, knocked firmly, and opened the door in response to Mycroft’s muffled invitation.

“Ah, John,” said Mycroft from behind a large desk covered in neat piles of paper. He was the most relaxed John had ever seen him, with his jacket hanging on the back of his chair and his shirt sleeves rolled up.“I’m glad you’re here.”

_Oh my god, that’s practically naked for Mycroft. Think about pink elephants._

“Yes, hello. I brought the files,” said John, waving the memory stick in the air and trying to ignore the way Mycroft casually leant back in his chair with his arm flung along the back.

_Think about elderly pink elephants._

“How kind.” Mycroft stretched out a long, elegant hand and flexed his fingers in invitation.

_Think about elderly pink elephants playing rugby, for Christ’s sake!_

John stepped forward to drop the memory stick into Mycroft’s palm and his fingers brushed the warm skin of his wrist. All thoughts of elephants disappeared in favour of a hyper-awareness of the scant few inches separating their bodies. Glancing around desperately for a distraction, his gaze landed on the nearest pile of paper and he could suddenly see, in gloriously vivid slow-motion, exactly how they’d scatter off the desk if he slapped his hands down for support while being taken vigorously from behind.

There was a soft cough, and John realised that Mycroft was staring at him.

“Well. That’s a lot of work for a Saturday,” he said after an awkward pause.

“End of term marking,” said Mycroft, still looking thoughtfully at John. “You know how it is.”

“Right,” said John, nodding slightly too enthusiastically. “Look, Mycroft, I-“

“Actually, I’m afraid I’m rather busy at the moment. Would you mind waiting outside for a few minutes?”

John blinked at Mycroft’s sudden dismissal. “Um ... ok.” 

He left the room. After waiting in the unseasonably warm corridor for a couple of minutes and replaying their brief conversation, he decided it would be for the best if he left the building as well (and, if he could find his passport, the country).

..........................

John made it halfway down the staircase before his phone rang. 

“Hi, Mycroft,” said John as soon as he answered. “Sorry, but I’ve just remembered that I have to ... do something.”

“Oh really?” said Mycroft, sounding amused. “Now that is a shame.”

He hung up before John could respond. After frowning at his phone for a moment, John realised that he had a text from Sherlock. He opened it to see a photo of a burning pillow which was almost certainly his.

As he stood there on the landing and contemplated his life choices to date, John looked out over the courtyard where various students were milling about in the late afternoon sunshine. He’d bet that none of them ever felt like a moderately stupid rat looking for cheese in a laboratory run by two mad, competing geniuses.

_Poor sods_ , he thought with feeling, and whistled as he put his phone away and walked briskly back upstairs.

The staircase was full of people making their way downstairs and John arrived back on the fifth floor to see several office doors swinging shut as the last few people made their way past him. For a moment he wondered if he’d missed a fire alarm, then shrugged and walked into Mycroft’s office through the open door.

“Close the door, would you?” said Mycroft without looking up from his laptop. John did as he was told. Mycroft typed furiously for a couple more minutes before shutting the laptop and looking up at John with an unreadable expression. 

“Everyone else has left,” said John. “Know anything about that?”

“I think they all found that they had places that they needed to be. Now, to more important matters,” said Mycroft, looking John up and down in a slow and deliberate way. “I have just submitted your final grades and am officially no longer your professor which, I’m sorry to say, means that it is no longer possible to realise most of your fantasies. Fortunately for you, I happen to be an excellent actor.”

John raised his eyebrows at Mycroft, who smiled serenely back.

“Oh, we can go out for dinner or something afterwards, if you like.”

John’s brain latched into the important word in that sentence. “Afterwards.”

“Yes,” said Mycroft as he loosened his tie, pulled it over his neck and carefully placed it on the desk. “Afterwards.”


	4. Chapter 4

After standing still for a few seconds -long enough that Mycroft started to seriously contemplate the possibility that he’d made an error in his calculations - John grinned, walked round and perched on the desk.

Mycroft stayed in his chair as he inspected John at an unhurried pace. From his wide-spread legs and tongue flicking unconsciously over his lips to the darkening of his eyes as Mycroft finally dragged his gaze back up, his desire was palpable. Mycroft almost wished that he could pause time on this moment of anticipation; pleasurable as their encounter promised to be, it would be difficult for it to live up to the excitement that crackled through him.

Instead he stood and brought his hand up to cup John’s face. It was the first time they’d touched since their handshake weeks before and he paused to savour the rasp of stubble against his palm before leaning down and kissing John with intent.

John’s soft lips parted at once as he brought one hand up to the back of Mycroft’s neck and took hold of his hip with the other. Mycroft licked into his mouth with delicate deliberation, and John groaned and thrust his tongue roughly against Mycroft’s in response before tugging him forward and down so that their bodies were pressed together between John’s open legs. 

The sheer number of sensations – the taste of tea and crisps (eaten no more than an hour before), the smell of fresh sweat, cheap soap and expensive deodorant (likely a Christmas gift), the heat of John’s body pressed against Mycroft’s chest and groin – threatened to overwhelm him.

“Tell me what you want,” he said, standing back to put a few inches between them.

John gave him a wicked look before dropping to his knees in lieu of an answer.

_Well, aren’t you a lovely, wanton thing_ , thought Mycroft with approval as he sat down, ran a hand through John’s fair hair and bent down to kiss him again. It was a leisurely, filthy kiss, full of tongues and teeth and accompanied by John’s rapacious hands stroking him through his trousers. Mycroft groaned as John managed to undo his belt and unzip his trousers without looking.

“You’re very keen,” he said, breathing hard as he sat back to give John some room to work with.

“I know,” said John cheerfully as he pulled out Mycroft’s rapidly hardening cock and licked his lips. “Do you mind?”

Mycroft stretched his arms up and crossed them casually behind his head.

“Oh, far be it from me to stop you enjoying yourself.”

John gave a soft snort before wrapping his lips round the swollen head and sinking down the shaft with more enthusiasm than finesse. Mycroft closed his eyes – the sight of John’s eager sucking was likely to bring this delicious encounter to an end far too soon. As it was, he was grateful to the insistent twinge of underwear elastic against his balls for awarding him some measure of control. He might be a dedicated practitioner of delayed gratification, but an athletic, promiscuous, orally fixated nineteen-year-old moaning around his prick was a bigger test of his self-control than any number of marshmallows.

Letting his hands fall down to tangle in the fine strands of John’s hair, Mycroft resisted thrusting up into John’s warm, wet and _very_ welcoming mouth – though he suspected that such an action wouldn’t be unwelcome, he had other plans for their afternoon’s romp. He let his eyes roam downwards in search of distractions and spied a welcome bump in his back pocket.

“Would you be so kind as to pass me the prophylactic so thoughtfully tucked into your back pocket?” he asked, stroking the soft, sparse hair at the nape of John’s neck.

John reached back, pulled out the condom packet and passed it up without taking his mouth off Mycroft’s cock. Mycroft took the packet and noted the neat reef knot at the end of the drawstring on John’s hooded jacket.

“You,” he said, twirling the condom packet between his fingers, “Were a scout.”

John held up his right hand in a three-finger salute as he continued bobbing his head up and down with admirable dedication. The innocent gesture was rather spoilt by the trail of saliva and pre-come meandering down over his fingers to his wrist.

“And were you such a charming tart then, as well?”

John flicked his hand round without breaking rhythm so that just his middle finger was left up, and Mycroft fell a little bit in love. He put the condom packet to one side and pulled John up for a deep, dirty kiss, revelling in the taste of his own juices mingled with the flavours of John’s mouth.

Mycroft broke away with reluctance and ran a hand through his hair in an attempt to regain his composure. 

“If you’re not bent over my desk in the next five minutes, there are going to be the most appalling consequences.”

John’s eyes glazed over briefly before he scrambled upright and turned around.

“You won’t need your clothes,” added Mycroft helpfully.

John stripped briskly and dropped his clothes straight onto the floor with a total lack of self-consciousness. Mycroft took the opportunity to divest himself of his own clothing but was so distracted by watching John undress that he was still wearing his shirt by the time John was bent over naked in front of him.

That called for a rapid rearrangement of priorities. He gave up on his shirt and inched forward on his wheeled office chair, scanning up and down John’s body to take in every inch of unevenly tanned skin before gently placing his hands on the back of John’s thighs.

Mycroft swept his hands up John’s legs in slow, silent worship until he reached his goal – the taut, muscular buttocks that were so gloriously positioned directly in front of him. 

“Good Lord,” he whispered while squeezing a good handful. “You are remarkably callipygian.”

“Is that a compliment?” asked John, fidgeting impatiently as he balanced on his forearms. “It sounds like a compliment. Also, what consequences?”

Mycroft ignored John’s pendulous erection in favour of spreading his buttocks apart and stroking his perineum with reverent thumbs. “Well, I would have been deprived of this sight, for one. And I believe you might paraphrase it as ‘nice arse’.”

John huffed a laugh. “That’s – _ah_ – a bit crude for you, isn’t it?”

“Hm?” he said distractedly, rolling John’s balls gently between his hands. “Oh, I wouldn’t say that. It would be crude if I expressed the desire to thrust between your freshly oiled buttocks until I spent all over your pretty back. It would be vulgar if I asked you to finger yourself while I watched, just so I could see your greedy hole twitch and spasm for want of a cock. And it would be downright obscene if I told you I’d like to drip dulce de leche into your arse and eat you out until you moaned like a twopenny whore.”

There was a beautiful moment of silence before John breathed again. “Fuck.”

Mycroft tutted. “Language, John. Now, keep your legs spread just like that while I fetch some lubrication. I won’t take you until I’ve had at least two fingers inside you, and I don’t think you’ll appreciate me doing that with only the aid of spit.” He paused to reflect on that. “Not that there’s any lack of that particular substance. It would take a stronger man than I not to salivate at the sight of your comely arsehole.”

Frankly, Mycroft was impressed that John managed to stay upright with all the trembling he was doing. He pulled open the bottom desk drawer with his right hand, using his left to stroke up and down John’s bare flank, and felt around until he found the small bottle of lubrication that he’d hidden there several weeks before when he was masturbating so frequently that he’d been in danger of chafing.

He noticed John looking back. “Eyes on your own work,” he said mischievously, at which John snapped his head back while his cock gave the most delightful twitch. Mycroft carefully pumped a small quantity of lube into the palm of his left hand and used it to liberally coat the fingers of his right before sliding them into the crack of John’s arse and caressing his tightly furled entrance. After a few minutes, Mycroft applied enough pressure to slip the tip of his index finger in.

John was _very_ tight. It took several minutes for Mycroft to work his finger in far enough to bend it slightly; he would have suspected that it was John’s first attempt at this particular act if it wasn’t for the lack of discernible anxiety. Mycroft was, however, certain from the tension in his back that his bottoming experience was limited. As much as the fantasy appealed, he wasn’t sure that the actual experience of being vigorously fucked over the desk would give John as much enjoyment as he clearly expected, and he wasn’t in the mood to enjoy afflicting pain. Still, John wouldn’t appreciate being coddled like a blushing virgin.

Mycroft considered the matter as he added a second finger and continued stretching and scissoring. He rather enjoyed taking his time with this – after all, it was only a matter of persuading the muscle that it wanted to relax, and persuasion happened to one of Mycroft’s more obvious talents. John’s erection (which had lessened upon first penetration) had now come back most satisfactorily.

“You’d like me to take you over the desk,” he mused, aiming deft strokes in the region of John’s prostate.

“If it’s not – ah _yes_ , fuck! – too much trouble.”

Mycroft hummed. “It does sound like rather a lot of effort.”

John stilled. “Excuse me? You do have two fingers up my bum right – _hng_ \- now. If you’re not going to fuck me then we need to - oh, _jesus_ , yes - have a serious chat about mixed signals.”

“You mistake my meaning,” said Mycroft as he pulled his fingers out and wiped them on his shirt-tail. “I have every intention of buggering you, but why should I do all the work?” He raised the arms of his chair up so that they were out of the way before picking the condom packet off the desk, opening it, and rolling it carefully onto his cock as John turned around. “In your own time.”

Mycroft couldn’t decide which he enjoyed looking at more as he languidly stroked himself – the drips of pre-come from the head of John’s cock, or the wonderful mix of arousal and irritation on his face. Really, having such an expressive face was just asking for trouble.

“So you want me to just … hop on,” said John with an incredulous look and a vague wave at Mycroft’s lap.

Mycroft shrugged and sped up his strokes. “That’s really up to you. I must say that I’m enjoying myself immensely at the moment.”

John looked at the chair. “You’ll need to lower that,” he said, fixing Mycroft with a look that positively dared him to make a height joke. Mycroft looked back with an innocent expression designed to suggest that he had never even considered the subject. Maintaining eye contact, he reached under his chair and released the lever that dropped the chair down three inches with a rush of air.

“Right then,” said John. He straddled Mycroft’s thighs, gripped the back of the chair and took a deep breath. Mycroft held the base of his cock steady with one hand, just in time for John to begin lowering himself, and used the other to grab John’s arse. He bit back a groan as John bore down, taking in the plump head with a sharp intake of breath before patiently inching his way down until he was fully seated. He stopped there with his eyes closed and let Mycroft’s legs take the weight. 

“How does that feel?” murmured Mycroft, unwilling to break the hush. It was an uncharacteristically irrational thought – after all, their respective breaths were loud enough, and there were plenty of distant sounds drifting in through the open window – and he filed it away for later consideration.

“Good, very... good,” said John vaguely as he flexed around Mycroft’s cock. He opened his eyes and smiled slightly. “Hi.”

“Hello,” said Mycroft, smiling back. He rubbed his thumb across one of John’s nipples and was rewarded with a sharp intake of breath.

“Is there a good reason that you’re still wearing your shirt?” asked John. He started rocking gently back and forth, and it was Mycroft’s turn to gasp.

“I had more – _ah_ – pressing matters to attend to,” said Mycroft as he struggled to stay still. “Would you like me to remove it?”

“Yes,” said John, leaning forward to press a quick, hard kiss against Mycroft’s lips. “I want to see you.”

Mycroft unbuttoned his shirt with slow deliberation and dropped it behind him. As soon as he’d done so, John raised himself up slightly before sinking quickly back down on his cock.

“Christ, _yes_ , like _that_ ,” he hissed as John repeated the action with a look of profound pleasure on his face before settling into a steady rhythm. Mycroft wasn’t normally a praying man, but he offered up prayers of thanks to any deities that might be listening for the miracle of a rugby-player’s strong thighs.

“I take it I’m going to be doing all the work then,” said John with a husky tone that completely failed to match the complaint in his words.

Mycroft took that as his cue to start fisting John’s thick, leaking erection, wringing more pre-come out of him with each skilful twist of his wrist. “You are younger and fitter than I am,” he proclaimed as loftily as he could manage with John riding him like something out of a wet dream. “It is only appropriate that you do the heavy lifting, as it were.”

“Oh, I don’t know,” said John, the sweat starting to trickle down his forehead as he fucked himself faster and faster on Mycroft’s cock. “You look pretty fit to me.” 

The leer with which John accompanied that pronouncement was in danger of making Mycroft blush. He decided that he had indulged John for long enough.

“You want me to fuck you.”

“That’s, ah, pretty much – _fuck_ – it, yes,” muttered John, moving as fast as he could with trembling thighs.

Mycroft placed his hands on John’s hips. “Very well. Touch yourself – yes, good, like that.” Planting his feet flat on the floor, he thrust upwards just as John pushed down. John cried out and let his head fall forward onto Mycroft’s shoulder, one hand pulling frantically at his cock. Mycroft ignored his desperate moans and concentrated on fucking him in earnest – the way he’d fantasised about, the way he should have taken him weeks ago. He was hitting John’s prostate dead-on, judging by the whimpers, which was fortunate as Mycroft wasn’t capable of changing position now.

He used his brutally tight grip on John’s hips to yank him down onto his cock as firmly as he was thrusting upwards. Barely registering the splash of warm semen on his stomach as John came with a shout, he thrust up as hard as he could, pounding relentlessly until his own orgasm hit him in a hot, sweet wave and he sank his teeth into John’s sweat-slick shoulder to keep from screaming.

Mycroft made a few more uncoordinated thrusts as his orgasm finished coursing through him before he finally came to a halt. He rested his forehead in the warm, damp crook of John’s neck and simply breathed.

“Not that I’m not comfortable,” said John after a while, “but I think I’m going to need to get up soon.”

Mycroft reluctantly sat back, and John climbed off with a wince. Mycroft carefully removed the used condom and disposed of it in the nearby bin. They re-dressed in silence.

“So,” said John as he watched Mycroft finish buttoning his shirt.

“Indeed,” said Mycroft, not unkindly.

“Where do you fancy for dinner?” asked John. “I’m guessing that you’re not a fan of Wetherspoons.”

Mycroft looped his tie back around his neck and looked at John. His eyes were bright and optimistic, and he quirked up one side of his mouth in a sly, inviting smile. He was young, and terribly naive, and had an image of Mycroft that bore very little resemblance to reality. The sensible thing to do would be to thank him for a lovely experience and gently turn him down.

“Peruvian, I think,” said Mycroft as he stood and picked his jacket off the back of his chair. “I know a place nearby that you’ll like.”

John fell into step as they left the office, whistling as he walked. Mycroft gave it a month at most.

But as they walked up the street, he placed a hand in the small of John’s back to guide him round a corner and permitted himself a quick, foolish smile.

............

Sherlock sat at the kitchen table with a half-eaten risotto pushed to the side and a catalogue of specialised laboratory equipment in front of him. He absent-mindedly flipped the pages as he ran back over the facts of the situation.

The first fact – that John had had a sexual liaison with Mycroft – was as obvious as it was appalling. John had gone to see Mycroft the previous afternoon and hadn’t returned home until this morning, freshly showered and smelling of Mycroft’s body wash under a heavy cloud of cheap body spray (newly purchased that morning, going by the receipt in his bag – a pathetically transparent attempt to hide his tracks). He’d also borne various tell-tale marks of at least two energetic encounters. Sherlock had been stunned into silence for several minutes by the sheer horror of the resulting mental images. He rather thought that this might be how normal people felt when confronted by decomposing corpses (and made a mental note to save this memory in case he needed to add verisimilitude to future dissembling).

The second, and more surprising fact, was that Mycroft had somehow managed to score the highest ever mark on the ‘John’s partner suitability’ index. Sherlock was still shocked by the result, but the evidence was incontrovertible: among other things, Mycroft had his own flat as a venue for sexual activities, a busy career which would stop him occupying too much of John’s time, and Sherlock had sufficient knowledge of Mycroft’s character and history to be confident that he would not treat John badly.

(A corollary of that last point, and a weighty fact in its own right, was that if Mycroft did hurt John in any way then Sherlock would have a completely valid excuse for tormenting him.)

“Are you going to finish that?” asked John. He was wearing an apron as he bustled about the kitchen cleaning, avoiding eye contact, and occasionally grinning fatuously when he thought he wasn’t being observed. 

Sherlock considered the remains of the risotto in front of him. “Perhaps,” he allowed. It really had been very nice. Which led to another unexpected fact – John felt guilty about fornicating with Sherlock’s brother and said guilt was currently manifesting itself in above-average food.

“Looking at new lab equipment?” said John as he took away Sherlock’s empty tea mug. “I thought the budget committee turned you down.”

And that led inexorably to the final and most interesting fact – that because Mycroft preferred monogamous relationships, and because Sherlock had what Mike called ‘a frankly unhealthy amount of influence over John’s life’, then, in the event of John choosing to continue their association, Sherlock essentially had power over Mycroft’s sex life (which he valued nearly as highly as his meals).This was an unprecedented amount of leverage to have over a man who himself had a considerable amount of leverage over the budget committee.

He looked thoughtfully at John, noticed a slight hitch in his walk, and turned to the most expensive section of the catalogue.

“Looks like it’s going to be a nice day,” said John, looking out of the window as he filled the kettle.

“Isn’t it just,” said Sherlock meaninglessly. He bookmarked several pages, put the catalogue down and beamed at John.

John looked at him suspiciously and put the kettle on.


End file.
